( 75 ) 



This after-ripening is accompanied bj' a considerable loss of weight 

 as is shown by the following figures. 



20 bananas broken from the bunch in a green state were placed 

 in a relatively cool spot (28° 0.) and weighed daily. 



The average weight per fruit was : 



after 01 2 345 (5 7 days 



145 143 142.5 142 141 139 138 137 grammes. 



Further, 10 green bananas of another variety were placed under 

 a glass bell jar into which a current of air free from carbonic acid 

 was introduced. The air leaving the bell jar was made to pass 

 through a drying apparatus and a Liebig potash bulb, which latter 

 was daily weighed. 



The fruits weighed originally 502.5 grammes 

 and after 4 days only . . 487.0 



therefore lost in weight . . 15.5 grammes 



The weight of the potash bulb increased 



the first day by 0.065 grammes 



the second day by 1.455 ,, 

 the third day by 0.540 

 the fourth day by 0.240 



Total increase 2.300 grammes 



So that the fruits gave off 2.3 grammes or 0.44 °/ °f carbonic 

 acid in four days. 



The chemical changes taking place during the after-ripening process 

 were now studied. Each day a banana was broken off from a green 

 unripe bunch of the fruit and when doing this care was taken to 

 select the specimen from the same row of the bunch trom which 

 the previous one had been taken and thus to obtain samples of the 

 same initial ripeness. The fruit was first peeled and rubbed to pulp 

 in a mortar. I determined the amount, of moisture by drying 10 

 grammes to a constant weight. Next 100 grammes of the pulp were 

 extracted with alcohol and the residue dried and weighed. I evapo- 

 rated the alcoholic solution after addition of a little calcium carbonate 

 with the object of neutralising the acids. The residue was dissolved 

 in water, additioned with a little solution of neutral lead acetate 

 and made up with water to 100 cM' in order to get the sugars in 

 the solution in the same concentration as that in which they originally 

 were present in the pulp. 1 determined polarisation and reducing 

 sugar in this solution both before and after inversion and calculated 

 from the figures obtained the amount of sucrose, glucose and fructose 



